Non-aqueous electrolyte solution for lithium ion secondary battery and lithium ion secondary battery having the same

Abstract

A non-aqueous electrolyte solution for a lithium ion secondary battery includes a lithium salt and an organic solvent. The organic solvent includes a carbonate compound, a linear ester compound and a linear ester decomposition inhibitor. This non-aqueous electrolyte solution restrains swelling while improving low temperature charging/discharging characteristics of the secondary battery in comparison to a conventional electrolyte since it contains the linear ester compound and the linear ester decomposition inhibitor. The non-aqueous electrolyte solution may be used in making a lithium ion secondary battery.

What is claimed is: 
     
       1. A non-aqueous electrolyte solution for a lithium ion secondary battery, which includes a lithium salt and an organic solvent,
 wherein the organic solvent includes 100 parts by weight of a carbonate compound, 100 to 250 parts by weight of a propionate-based ester compound and 0.1 to 20 parts by weight of an inhibitor to inhibit decomposition of the propionate-based ester compound, 
 wherein the propionate-based ester compound is expressed by the following Chemical Formula 1 
 
       
         
           
           
               
               
           
         
         in which R 1  is a CH 3 CH 2  group, and R 2  is a linear or branched C1-5 alkyl group, and R 1  and/or R 2  may be unsubstituted or substituted with at least one halogen, and 
         wherein the inhibitor is any one material or a mixture of at least two materials selected from the group consisting of pyrrole, thiophene, aniline, biphenyl, cyclohexyl benzene, fluoro-toluene, tris(trifluoroethyl)phosphate, γ-butyrolactone, γ-valerolactone, butyronitrile, hexanenitrile, succinonitrile, adiponitrile, valeronitrile, siloxane, silane and halogenated compounds thereof, and 
         wherein the carbonate compound is any one material or a mixture of at least two materials selected from the group consisting of ethylene carbonate, 3-fluoroethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate and butylene carbonate. 
       
     
     
       2. The non-aqueous electrolyte solution for a lithium ion secondary battery according to  claim 1 ,
 wherein the propionate-based ester compound is selected from the group consisting of methyl propionate, ethyl propionate, propyl propionate, and butyl propionate. 
 
     
     
       3. The non-aqueous electrolyte solution for a lithium ion secondary battery according to  claim 1 ,
 wherein the lithium salt is any one material or a mixture of at least two materials selected from the group consisting of LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , CF 3 SO 3 Li and LiC(CF 3 SO 2 ) 3 . 
 
     
     
       4. A lithium ion secondary battery, which includes an electrode structure having a cathode, an anode and a separator interposed between the cathode and the anode, and a non-aqueous electrolyte solution injected into the electrode structure,
 wherein the non-aqueous electrolyte solution is a non-aqueous electrolyte solution for a lithium ion secondary battery defined in  claim 1 . 
 
     
     
       5. A non-aqueous electrolyte solution for a lithium ion secondary battery, which includes a lithium salt and an organic solvent,
 wherein the organic solvent includes 100 parts by weight of a carbonate compound, 100 to 250 parts by weight of a propionate ester compound and 0.1 to 20 parts by weight of an inhibitor to inhibit decomposition of the propionate ester compound, 
 wherein the propionate ester compound is ethyl propionate or methyl propionate, and 
 wherein the inhibitor is any one material or a mixture of at least two materials selected from biphenyl, cyclohexyl benzene, tris(trifluoroethyl)phosphate, γ-butyrolactone, succinonitrile, valeronitrile, siloxane, and silane, and 
 wherein the carbonate compound is any one material or a mixture of at least two materials selected from the group consisting of ethylene carbonate, 3-fluoroethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate and butylene carbonate. 
 
     
     
       6. A non-aqueous electrolyte solution for a lithium ion secondary battery, which includes a lithium salt and an organic solvent,
 wherein the organic solvent includes 100 parts by weight of a carbonate compound, 100 to 250 parts by weight of a propionate ester compound and 0.1 to 20 parts by weight of an inhibitor to inhibit decomposition of the propionate ester compound, 
 wherein the propionate ester compound is ethyl propionate, and 
 wherein the inhibitor is any one material or a mixture of at least two materials selected from biphenyl, cyclohexyl benzene, tris(trifluoroethyl)phosphate, γ-butyrolactone, succinonitrile, valeronitrile, siloxane, and silane, and 
 wherein the carbonate compound is any one material or a mixture of at least two materials selected from the group consisting of ethylene carbonate, 3-fluoroethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate and butylene carbonate.